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Historically, respiratory induced motion has made renal radiotherapy difficult due to the potential risk of additional toxicities to the patient due to tumor movement. The use of deep inspiration breath holds (DIBH) in congruence with magnetic resonance guided radiotherapy (MRgRT) may be an effective method to manage tumor and organ at risk (OAR) motion and deliver radiation safer and more effectively. The purpose of this case study was to evaluate the effectiveness of DIBH in sparing radiation dose to colon and small bowel during MRgRT of right sided renal cell carcinoma (RCC). The goals were to reduce radiation dose to colon and small bowel during RCC treatment with these motion management techniques. A retrospective case study of a patient with oligoprogression in the postoperative renal fossa was found to be a candidate for DIBH using MRgRT. Treatment planning called for motion management and real-time imaging in order to safely treat the tumor volume. Results were evaluated by the achievement of specific dosimetric criteria and tolerances and the regression of disease in the renal fossa. The use of real-time imaging and simultaneous motion management proved to be effective tools for the treatment of RCC. This radiation therapy treatment resulted in the elimination of malignancy at the primary site of disease. [ABSTRACT FROM AUTHOR]

The purpose of this case study is to communicate a technique on treating the re-irradiation of squamous cell carcinoma (SCC) of anal canal with proton fields matched with electron fields to spare prostatic urethra. A 76-year old male presented with a secondary radiation-induced malignancy as a result of prostate brachytherapy seeds irradiation 10 years prior. A rectal examination revealed a bulky tumor at the top of the anal canal involving the left superior-most aspect of the anal canal extending superiorly into the rectum. The inferior extent was palpable approximately 3 cm from the anal verge and the superior extent of the mass measured greater than 5 cm in the superior-inferior dimension. Chemoradiation was suggested since the patient was opposed to abdominoperineal resection (APR) and colostomy. The use of proton therapy matching with electron fields in the re-irradiation setting could help reduce the complications. A 2 lateral proton beams were designed to treat the bulky tumor volume with 2 electron beams treating the nodal volumes. This complication of treatment fields helped spare the prostatic urethra and reduced the risk of urinary obstruction in the future. [ABSTRACT FROM AUTHOR]

The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient׳s neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient׳s data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a painful, degenerative disease that affects the tissues of the joint spaces, such as the shoulder. Conventional medical treatment options, such as corticosteroid injections and anti-inflammatory medications, are not always sufficient to alleviate the symptoms from this disease. Low dose radiotherapy is a newer treatment option for patients with shoulder osteoarthritis and has shown positive outcomes. However, the problem is that there is a paucity of literature about treatment planning considerations for this new treatment option. The purpose of this case study was to provide an example of treatment planning techniques and considerations for shoulder osteoarthritis. Treatment techniques for shoulder LDRT, such as treatment field borders, prescribed dose, beam arrangements, appropriate beam energy, and special considerations are discussed. [ABSTRACT FROM AUTHOR]